Modular systems having addressable or non-addressable slots for receiving a plurality of individual modules are employed in many technology related areas. For instance, modular power supplies, made up of a collection of separate, parallel-coupled power supply modules under unified control, are enjoying ever-widening application today, primarily due to their ability to deliver more power more reliably, because the load is shared more or less evenly among the separate power supply modules. The modular architecture is also more flexible, allowing individual modules to be easily removed and replaced to accommodate changes in power supply requirements. Finally, the modular architecture allows failed modules to be easily replaced.
Conventionally, the power supply may employ multiple parallel-coupled converters in separate modules that convert an AC input voltage to a DC output voltage. Again, the power supply may employ multiple converters in separate modules to increase the overall capacity and reliability of the power supply. The converters, in such a system, share the load to, among other things, evenly distribute stresses between the separate modules, while maintaining a regulated output to the load. Also, when a failure occurs in a modular system, it is possible to identify and shut-down the failed unit without affecting the other parallel connected units and minimizing the overall affects on the output of the power supply. In many modular power supplies, a centralized controller is employed to monitor the individual modules and initialize the power supply modules as they are incorporated into the power supply. Separate physical links between the centralized controller and each individual power supply module are employed to transmit the information therebetween.
While uniform power distribution or load sharing is a goal of parallel converters in the modular power supply, several factors contribute to non-uniform distribution. For instance, as component tolerances and the characteristics of the components change due to uneven aging and different physical conditions, the power distribution therefrom also changes. Also, the non-identical characteristics of the electrical conductors (e.g., separate physical links of varying length) connecting the individual converter modules to the load contribute to the non-uniform power distribution from the power supply modules. While the deterioration of the individual component modules due to uneven aging of the modules therein, for instance, cannot be cured by the system, there are other areas where the modular system may be improved to increase an overall reliability of the power supply.
For instance, employing a serial bus with separate connectors to each individual module removes a portion of the non-identical characteristics of the electrical conductors connected to each module. However, there still must be a system that manages the transmission of information between the centralized controller and the individual modules. There also must be a protocol that detects, assigns addresses and initializes new stations as they are incorporated into the power supply. One such initialization alternative is to employ operator-setable switches to physically and externally address a new station as it is added to the power supply. Alternatively, still other protocols, employing collision detection, may be employed to overcome address resolution problems. However, it is desirable to employ a system protocol that does not require either prior configuration or collision detection circuitry. For the same, or very different reasons, modular systems are applicable to a vast array of technology related areas and, as a result, efforts are ongoing to enhance the operation thereof.
Accordingly, what is needed in the art is a protocol for a modular system that automatically detects, assigns addresses to and initializes components in the modular system and is operable to monitor an operation of the components in the modules of the modular system.